title: At what age can human oocytes be obtained?
abstract: OBJECTIVE
  To determine whether oocyte retrieval and in vitro maturation (IVM) is effective in girls undergoing fertility preservation before cancer treatment.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Tertiary university medical center.
  
  
  METHODS
  Patients <or=20 years old before gonadotoxic chemotherapy undergoing ovarian cortex cryopreservation.
  
  
  METHODS
  Before ovarian cortex cryopreservation, oocytes in all observed follicles were aspirated, matured in vitro, and cryopreserved.
  
  
  METHODS
  Maturation of oocytes.
  
  
  RESULTS
  One hundred seventy-nine oocytes were detected in 17/19 patients (89%) aged 5-20 years. We found 7, 8, and 17 oocytes in patients 5, 8, and 10 years old, respectively. The median number of oocytes per patient was 9 (0-37). Maturation rate was 45/133 oocytes (34%). In total, 81 oocytes were cryopreserved. We cryopreserved 4 of 12 detected, 4 of 9 detected, 1 of 8 detected, and 4 of 9 detected IVM oocytes for patients aged 5-10, 11-14, 15-17, and 18-20 years old, respectively.
  
  
  CONCLUSIONS
  Patients undergoing ovarian cryopreservation could benefit from supplementary oocyte aspiration from the cortex. Surprisingly, oocytes were detected even in young premenarcheal girls. The number of oocytes detected, matured, and cryopreserved was not age dependent. Retrieved oocytes can be matured in vitro and cryopreserved. Because no pregnancy has yet resulted from this procedure it should be considered to be experimental. We describe the youngest patients to undergo ovum collection, IVM, and oocyte cryopreservation.
authors.affiliation: Department of Obstetrics and Gynecology, Hadassah Hebrew University Medical Center, Jerusalem, Israel. arielr2@hadassah.org.il
authors.forename: Ariel
authors.initials: A
authors.lastname: Revel
authors.forename: Shoshana
authors.initials: S
authors.lastname: Revel-Vilk
authors.forename: Einat
authors.initials: E
authors.lastname: Aizenman
authors.forename: Anat
authors.initials: A
authors.lastname: Porat-Katz
authors.forename: Anat
authors.initials: A
authors.lastname: Safran
authors.forename: Assaf
authors.initials: A
authors.lastname: Ben-Meir
authors.forename: Michael
authors.initials: M
authors.lastname: Weintraub
authors.forename: Michael
authors.initials: M
authors.lastname: Shapira
authors.forename: Hanna
authors.initials: H
authors.lastname: Achache
authors.forename: Neri
authors.initials: N
authors.lastname: Laufer
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000375:Aging / Q000473:pathology* / Q000502:physiology*; D002470:Cell Survival; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D015925:Cryopreservation / Q000379:methods*; D005260:Female; D006801:Humans; D054315:Oocyte Retrieval / Q000379:methods*; D009865:Oocytes / Q000166:cytology* / Q000502:physiology*; D055815:Young Adult